This Sexually Transmitted Diseases Cooperative Research Center will emphasize prevention of selected STDs and the consequences of STDs. In particular we are stressing STDs which have significant adverse impact on the health of women. With this approach we will identify ways in which the burden of complications associated with STDs that disproportionately result in adverse effects on the reproductive health of women can be reduced. To achieve this goal we will be taking several approaches. Two intervention studies, an indirect and direct approach, will be undertaken to prevent acquisition of Chlamydia, gonorrhoeae and bacterial vaginosis (BV) and thereby the complications associated with these STDs. In a biologic intervention approach use of a Lactobacillus suppository will be assessed in a double-blinded placebo-controlled trial to prevent infection with BV, N gonorrhoeae and C. trachomatis. By studying risk perception of sexual behavior in adolescents and developing interventions for promoting safer sexual behaviors, including condom use, we are attempting to prevent the acquisition of STDs in adolescents. Determining the molecular basis for the association of Trichomonas vaginalis and premature rupture of membranes (PROM) will provide information relevant to preventing adverse pregnancy outcomes, including preterm delivery, low birth weight and PROM. In summary, these multiple approaches focus on our unifying goal of protecting the reproductive health of young women from the sequelae of STDs.